Breakdown-detector for rail-joint insulation.



G. P. THUBBEFI.

BREAKDOWN DETECTOR FOR RAIL JOINT INSULATION.

APPLICATION HLE'D NOV. 1. 191

1,232,441 a Patented July 3, 1917.

2 SHEETSSHEET I.

Witnesses Inventor,

Attorheys,

e. 'P. THURBE R BREAKDOWN DETECTOR FOR RAIL JOINT INSULATION- APPLICATION FILED NOV-1'19]!- Patented Ju s, 1917.

2 SHEETS-SHEET 2.

*1 a? 3 n g '-V Q s TQQ 3% 5 T 11 A N 7 & g E N lnventoig,

, ,Y, Attorneys,

GUY I. THURIBER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 AUTOMATIC TRAIN CONTROL & SIGNAL COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

BREAKDOWN-DETECTOR FOR RAIL-JOINT INSULATION.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed. November 1, 1911. Serial No. 658,030.

To all whom it may concern:

Be it known that I, GUY P. THURBER, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Breakdown-Detector for Rail- Joint Insulation, of which the following is a specification.

This invention relates to an improvement in break down detectors for railjoint insulation, and the primary object of the invention is the provision of a detector especially designed for use in connection with the safety. signal systems employing separated or insulated blocks, wherein the rails at abutting or adjoining signal blocks are connected by insulation with loop connections or inductive bonds therearound or across the insulation.

A further object of the invention is the provision of a detector, which will immediately notify the location of the break in the insulation, so that the cause of the trouble may be quickly located and mended.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made Within the scope of what is claimed without departing from the spirit of the invention.

In the drawings Figure 1 is a diagrammatic View of a signal station along a single track electric railway with the break down detector mechanism shown in operable position.

Fig. 2 is a similar view of a modified form of break down detector for rail-joint insulation.

Referring to the drawings, and particularly to Figs. 1 and 2 thereof, A designates the signal station separated at points a, by insulated joints, into a block A and a block A. These blocks at their opposite ends are insulated from the connecting or adjacent blocks by means of other insulated joints. The transformer D supplied with current from the line wires 100 and 101, supplies current to the rails of block A through the respective wires D, and E, respectively.

The sections 1 and 2 of the rails, and sec tions 3 and l of the rails, are connected by the two respective short rail sections 5 and 6, and are insulated from each otherby means of the insulated joints 7, 8, 9 and 10 (see Fig. 1). For the purpose of detecting the breaking down of the insulation of these joints, detector plates F, F, F 2 and F are interposed in the joints and the track current is led through these detector plates. The detector plates are insulated from the rail lengths 1, 2, 3 and l by the additional insulation 7 9, 8 and 10 respectively. The insulated joints just described thus consist in each case of an insulated joint having interposed therein a metallic detector plate.

Around the insulated joints' of the two rails 12 and 34, are connected the noninductive bonds 11 and 12, while connected to the detector plate of the insulated joints 7 and 9 are the wires 13, 14 and 15, the wire 13 connecting the plate to the rail 3, while the wire 15 connects the plate to the rail 4. The wire 16 connects the detector plate of the joint 8, to the rail 1, the wire 17 connecting the detector plates of the joints8 and 10, while the detector plate in the joints 10, is connected to the rail 2 by means of the wire 18. V

By this arrangement of connections, it will be evident that any broken insulation on either side of the metal detector plates will immediately short circuit the rails, and thus shunt the current from the track relay 15, at the other end of the block. By this means .an absolute protection against any possibility of a break down on any one of the joints, is provided, and such break down will always give a danger signal.

By having the joints connected together and also cross connected to the rails at each end of the insulated section, two paths for the detector current'are provided. The first path is from the secondary of transformer D, through the wire D, to rail 4, cross-connection 15, detector plate'F, wire 14, detector plate F, cross-connection 13, rail 3, conductor 30, to the coil 31 of track relay 15, conductor 32, to rail 1, then through oross-connection 16, detector plate F wire 17, detector plateF cross-connection 18,

rail 2, and connection E, to the other side of the transformer secondary. The other path is the same as just described except the current instead of flowing through the crossconnections simply flows through the noninductive bonds 11 and 12extending around the insulated joints. This provides double protection against a broken wire. In practice it has been found that the Wires 14; and 17 may be dispensed with when impedance bonds with relay and transformer have been provided, as shown in Fig. 1, this being the preferred arrangement. I, however, connect the detectors up with these wires as an extra precaution in spanning the entire short section instead of connecting to the short rail.

The circuit breaker solenoid 19, is connected by Wires 19, through the armature of the track relay 15, and circuit maker 17 at the station (this arrangement is illustrated in Fig. This circuit breaker 19 normally actuates the two armatures 20 and 20, which are connected by leads 21 and 21, respectively to the rails 36,- and 15, respectively, around the joints at insulated joints 7 and 8.

In the form of break-down detector, as shown in Fig. 2, the usual method of protecting insulated joints where alternating current is used to operate the signals, is employed, by reversing the polarity .of the transformer connections to the track at the ends of adjacent blocks. This forms a means of unbalancing the track relay 1 whenever a break down joint occurs. In this form such action, will open the track relay, and give the signal in the usual manner;

In this case the circuit breaker 22, has its leads 23, connected on each side of the insulated joint 24 at the stopping point J, in the track, and it is evident that the two in sulated rails in this short section are connected by the bond wire 25, and also that the line leading from the short insulated rail section to the circuit breaker 22, has a shunt connection 27, attached to a back contact of the circuit breaker. Leading from another back contact 28, and having the same armature controls, is a line conductor 29, connected to one side of the track relay 6, in the adj acent block.

In this instance should a break occur at any one of the four insulated joints in this short rail section, and by reason of the circuit breaker 22 opening at each transmission of a signal, the contact terminals" of wires 29 27, are short circuited, making 'a direct connection through the broken down insulated joint to one side of the track relay 6,

'in' the adjacent block, and throwing into said relay 6 a current connected to the rails in reverse direction to the one normally controlling track relay 6. This throws a counter electromotive force of a difierent phase,

and imbalances said track relay 6, control ling the circuit breaker 22, and therefore will not allow it to close again. By this means, the circuit breaker will remain open until the trouble is remedied;

Y The full operation of the break down detector will be best understood from a consideration of Figs. 1 and 2. Assuming for illustrative purposes that the insulation at 9 should breakdown, then the current from the secondary of transformer D instead of flowing through the various connections pre viously described, to the track relay 15,,will be short-circuited through the following path: from the secondary of transformer D, through Wile E, rail 2, defective insulation 9, cross-connection 15, to rail l, and then through Wire D, back to theotherside of the secondary. The track relay being thus deprived of current in one of its coils (31) releases its armatures and thereby ruptures certain line circuits which extend from this station to one or more stations in front or in rear. A break down of the; insulation at will have the same effect as just described because in such an event the crossconnection' 18 will form a Virtual short-circuit between the two rails 2 and 3 sothat the current from the secondary of transformer D will be short-circuited across the rails,instead of flowing through the various connections on to the track relay 15. A break down of the insulation at 8 will also cause a deenergization of track relay'15, for in such a case thecurrent from the secondary o'f transformer D will flow frointhe wire E, rail 2, eross connection 18, detector plate F connection 17,- detector plate F through the broken down insulation 8, to rail 3, and thence by way of cross-connection 13, detector plate F, connection 141, detector plate F, cross-connection 15, rail 4, and connection D, to the other side of the transformer sec-- ondary. The track relay being thus deprived of its supply of current releases its armatures, which thereupon break certain circuits. A like eflect follows upon the breaking down of the insulation at 7;, for in such an event the cross-connection 13 forms a virtual short-circuit between rails 1 and 3,

and the current from transformer D flows through this short-circuit and thereby 'deprives track relay of itsproper supply of current. A break down of the insulation. at 10, permits current to flow fr'oin connection E and the rail 2 through cross-connection 18 and the defective joint, to'the short rail length 6, then through the wires 21 and armature of the jumper circuit, to rail 3, from this rail through the cross-connection 13 detector plate F, connection 14L, detector plate F, cross-connectionlti, to rail 4, and fronrthere through wire D to the other side of the transformer secondary. It will be seen that the track relay 15 is in this case also deprived of current and therefore acts to break certain circuits which it controls. If the insulation at 9 becomes defective, the How of current will be from conductor E and rail 2, through the non-inductive bond 11, the wires 21' and armature 20 of the jumper circuit to the short rail length 5, thence through the defective insulation 9 to detector plate F and through cross-connection 15 to the rail 4, and by way of conductor D back to the transformer secondary. In this case also the track relay is deprived of current. Practically the same result follows when the insulation at 7 or 8 becomes defective. Thus if insulation 8 should break down, current will flow from rail 2 through cross-connection 18, detector plate F broken down insulation 8 to short rail 6, thence by wires 21 and armature 20 of the jumper circuit, to rail 3, through cross-connection 13, detector plate F, wire 14-, detector plate F, cross-connection 15, to rail 4, and then by conductor D back to the secondary of the transformer. In each case it will be seen the track relay is aifected by the breakdown of the insulation and when so affected it operates to rupture certain circuits. The rupturing of these circuits by the track relay causes the sending of certain danger indications to one or more blocks in front or in rear.

What is claimed, is z- 1. In combination, track rails, a track circuit including said rails, an insulated section in said rails, and means for detecting a breakdown of the insulation for said section comprising a conductor embedded in the insulation for each joint of the insulated section and connected to the opposite rail outside the section.

2. In combination, track rails, an insulated train controlling section in said rails, a track circuit having a source at one side and an electro-responsive device at the other side of said insulated section, means for bridging the track circuit around said insulated section, and a conductor embedded in the insulation for each joint of said section and connected to the opposite rail outside the section, whereby a breakdown of the insulation for any of said joints will affect said electro-responsive device.

3. In combination with a traffic track, insulated joints dividing the rails of said track into local blocks and intervening sections, and means for detecting a break down of the insulation between a block and an intervening section comprising a conductor interposed in each of said joints and insulated from the adjacent rail ends, and a cross-connection from. said conductors to each other and to the opposite rails of the track outside of said intervening sections.

4:. In combination, a traflic track, insulated joints dividing both the rails of the track into local blocks and intervening sections of track, electro-responsive devices connected to the rails at points outside a local block, means for impressing electrical energy upon the rails outside the local block and in the same section with the electro-responsive devices, connections around insulated joints in the two opposite rails, c0nductors interposed in the joints and insulated on both sides from adjacent rail ends, cross-connections from each conductor to the opposite rail at a point outside the local block and in the same section as the source and electro-responsive devices, and connections bridging the local block connected be tween the conductors in the joints of each rail.

5. In combination, a trafiic track, insulated joints dividing both the rails of the track into local blocks and intervening sec tions, electro-responsive devices connected to the rails at points outside a local block, means for impressing electrical energy upon the rails outside the local block and in the same section as the electro-responsive devices, connections around insulated joints in the two opposite rails, conductors interposed in the joints and insulated on both sides from adjacent rail ends, cross-connections from each conductor to the other conductor and to the opposite rail at a point outside the local block, and bonds electrically uniting the sections of the track at opposite ends of the local block.

6. In combination, traffic rails, an insulated section in said rails, a loop circuit arranged to connect or disconnect said insulated section to said rails to control a train passing over said section, a track circuit including said rails, paths for conveying said track circuit through said section including a conductor leading from each rail at one side of said section through the insulated joints of the opposite rail section and back to the first rail at the other side of said sec tion.

7. In combination, trafiic rails, insulated sections in said rails, conductors interposed in the insulation defining said sections, means for impressing current upon the rails at one side of said section, an electro-responsive device connected to the rails at the other side of said section, and a path for said current through said insulated section leading from each rail at one side of said section through the conductors interposed in the insulated joints of the opposite rail and back to the same rail at the other side of said section, whereby a break down of said insulation will affect said electro-responsive device.

8. A train control system comprising: track rails, insulated sections in said track rails, conductors connecting the track rails around said insulated sections, one of said conductors connecting one rail at both sides of the insulated section and passing, through the insulation at both ends of the insulated section in the opposite rail, and another of said conductors connecting the other rail at both sides of the insulated section and passing through the insulation at both ends of the insulated section inthe opposite rail, whereby a break down of the insulation between the insulated section and an adjacent local block will be detected. v

9. A train control system comprising: track rails divided by insulation into blocks and connected to form a continuous path for propulsion current, insulated sections in said track rails Within said blocks, conductors connecting the track rails around said insnlated sections, one of said conductors contion at both ends of the insulated section in the opposite rail, and another ofsai'd conductors connectingthe other rail at both sides of the insulated section and passing through the insulation at both ends of the insulated section in the opposite rail, Whereby a breakdown of the insulation between the insulated section and adjacent local block will be detected.

In testimony that I claim the foregoing as my own, I have hereto afiiked my signature in the presence of two witnesses.

GUY P. THURBER.

Witnesses CATH RINE LYNCH, MARGE M. DANAHY.

Copies of this patent may be obtained for five cents each, lay addressing the Commissioner of Patents, Washington, D. 0. 

